Cell-mediated immune responses are initiated by T lymphocytes that are themselves stimulated by cognate peptides bound to MHC molecules on antigen-presenting cells (APC). T-cell activation is generally self-limited as activated T cells express receptors such as PD-1 (also known as PDCD-1) that mediate inhibitory signals from the APC. PD-1 can bind two different but related ligands, PD-L1 and PD-L2, both of which are thought act as a negative regulator of T cell activation. However, it has been suggested that PD-L2 can act to stimulate an immunogenic response through an alternative receptor from PD-1.ProSci's Risk-FreeTM antibodies are mouse monoclonal antibodies made to improve in vivo studies. Unlike antibodies developed using proteins made in yeast or bacteria, Risk-FreeTM antibodies are developed with antigens expressed in mammalian cell lines, giving the most native post-translational modifications to the protein. Validated for flow cytometry and ELISA Rigorously tested for the following applications: Immunoblot Immunohistochemistry Immunocytochemistry Immunofluorescence Multiple antibodies per target allowing the user to choose the best antibody for their application Available individually or as a set Risk-FreeTM means they are guaranteed to work for their approved applications